Filter media and filters for the sequestration of carbon dioxide are disclosed. The carbon dioxide sequestering filter media incorporate silicate minerals, and the carbon dioxide sequestering filters incorporate carbon dioxide sequestering filter media. Filters using only carbon dioxide sequestering media and filters combining carbon dioxide sequestering media with traditional air filter media are disclosed. The carbon dioxide sequestering filters may be used instead of traditional air filters in residential, commercial and industrial applications.

The present invention relates to an adsorbent comprising an alumina support and at least one alkali element, said adsorbent being obtained by introducing at least one alkali element, identical to or different from sodium, onto an alumina support the sodium content of which, expressed as Na.sub.2O equivalent, before the introduction of the alkali element or elements, is comprised between 1000 and 5000 ppm by weight with respect to the total weight of the support. The invention also relates to processes for the preparation of said adsorbent and use thereof in a process for the elimination of acidic molecules such as COS and/or CO.sub.2.

Provided are a reusable polymeric material for removing siloxane compounds in biogas, a method for removing siloxane using the same, and an apparatus therefor, and more particularly, a polyacrylate-based polymer absorbent for removing siloxane compounds in biogas and a method for removing siloxane compounds in biogas. The method for removing siloxane compounds in biogas includes (a) providing the biogas, and b) absorbing the siloxane compounds in a polymer absorbent by passing the biogas through the polymer absorbent according to any one of claims 1 to 5.

A method for removing at least one contaminant from a fluid stream by filtering the fluid stream with a filtration medium. The filtration medium includes an impregnate. The impregnate includes a surfactant such as sulfamic acid. The medium has from about 0.1 to about 25% by weight of impregnate. The method is useful for removing one or more volatile organic compounds, particularly formaldehyde, from the fluid stream. In some embodiments, the method includes removing at least two volatile organic compound contaminants from the fluid stream.

Composite materials and methods of preparing C0.sub.2 capture include: (1) a porous solid support comprising a plurality of porous channels; and (2) a nucleophilic source associated with the porous channels of the porous solid support. The nucleophilic source is capable of converting the captured C0.sub.2 to poly(C0.sub.2). Methods of capturing C0.sub.2 from an environment include associating the environment with the aforementioned composite materials to lead to the capture of C0.sub.2 from the environment. Such methods may also include a step of releasing the captured C0.sub.2 from the composite material. The associating step comprises a conversion of the captured C0.sub.2 to poly(C0.sub.2) in the composite material. A releasing step may also include a depolymerization of the formed poly(C0.sub.2).

Structured adsorbent beds comprising a high cell density substrate, such as greater than about 1040 cpsi, and a coating comprising adsorbent particles, such as DDR and a binder, such as SiO.sub.2 are provided herein. Methods of preparing the structured adsorbent bed and gas separation processes using the structured adsorbent bed are also provided herein.

An oxygen absorbing agent composition including at least one type of a compound having an indane skeleton represented by the following general formula (1) and a transition metal catalyst: ##STR00001##

A gas separation unit for the separation of carbon dioxide from air is proposed for use in a cyclic adsorption/desorption process and using a loose particulate sorbent material. Sorbent material is arranged in at least two stacked layers, and each layer comprises two sheets of a flexible fabric material which is gas permeable but impermeable to the loose sorbent material. The sheets are arranged parallel defining an inlet face and an outlet face, are arranged with a distance in the range of 0.5-2.5 cm, and are enclosing a cavity in which the sorbent material is located. Said layers are arranged in the unit such that the inflow passes through the inlet face, subsequently through the particular sorbent material located in the cavity of the respective layer, subsequently to exit the layer through the outlet face to form the gas outflow.

The invention provides a composite material formed from an inorganic mesoporous, or mesoporous-like, material that is dispersed throughout a polymeric matrix formed by a crosslinked polymer that has acidic- or basic-residues and which may also optionally have further acidic- or basic-residues grafted onto the inorganic mesoporous material. The resulting composite material may be used to remove acidic or basic impurities from a gas in need thereof and can be easily regenerated.

A chemical absorbent comprising a hydrated mixture of a major proportion of a pharmaceutically acceptable hydroxide of a Group II metal and a minor proportion of a Group I metal-containing zeolite. The chemical absorbent is substantially free of hydroxides of Group I metals.